Treatment of motor fuel



Patented Sept. 17,

UNITED STATES TREATMENT or MOTOR roan FranklinW.McCurry,Wichita,Kans.

No Drawing.

17 Claims.

The present invention relates to an improved motor fuel which is resistant to changes resulting from storage, exposure to light, or both, as well as to the process of producing such a motor fuel.

It has long been recognized that modernmotor fuels, which, as is well known, contain sulfur compounds and unsaturated hydrocarbons, are unstable in the following respects, namely, that upon storage they'will deposit gums, lose their color, become cloudy or milky and, in some instances, develop therein formed precipitates. It is also known that when attempts are made to increase the antidetonant value, sometimes known 'as the octane rating, of such fuels, as for ex- 1 ample the addition thereto of small amounts of antidetonantfor instance, metallo-organic compounds exemplified by tetraethyl lead and nickel or iron carbonyl, they often lose their transparency when exposed to light, becoming cloudy and discolored and finally depositing precipitates. It will be self -evident that such deterioration of motor fuels is highly undesirable, as it not only militates against sale to the public-which has been educated to brightly colored, sparkling, transparent motor fuels-but also interferes with the carburetingmechanisms employed in connection with internal combustion motors such as those on motor cars, motorboats, airplanes, and other craft. It has been found, for instance, that cracked hydrocarbon motor fuels containing, for example, tetraethyl lead are unstable against the influence of light unless there is incorporated therewith some additional substance which will inhibit, re-

tard or prevent the oxidation changes or other changes produced by the incidenceof light rays. It has also been found that when such motor fuels deteriorate under the influence of light or storage, or both, a considerable-portion of the therein .contained metallo-organic antidetonants become converted into insoluble substances of metallic com- 40 pounds which separate and, if employed in the carbureting mechanisms of the therewith associated internal combustion motors, tend to clog the carburetor and the internal portions of the r 45 moto 5 Many efforts have been made in'the past to overcome these difliculties, and a number of or-.

Application November 21, 1938, Serial No. 241,514

compounds in particular. Thus, while it is possible to prevent the formation of gums for a considerable period, the compounds which prevent the gum formation'are quite ineffective in preventing the decomposition of the antideto'nants when exposed to light.

Applicant has discovered that by the addition to motor fuels of the above characteristics of very minute amounts of products produbed by the activation of fatty oils he can produce a motor fuel whose antiknock and other valuable characteristics will be preserved for a long time, even under severe conditions of incident light and of storage time. The substances employed .by applicant for this purpose have not been isolated per se but are found in-fatty oils particularly, when these have been subjected to activation such as is produced by heat oxidation to such an extent that they have become greatly increased in viscosity, without however having carried the oxidation anywhere near completion. The polymerization of fatty oils also effects such activation. Ozonization is, for the purposes of the present invention, a further means of activation. Among the fatty oils suitable for the purpose of carrying out the present invention, the fish oilshave been found to be particularly efiicacious, although certain vegetable oils have also been found to be very useful for the purpose. Among the latter may be mentioned corn oil, soy bean oil, cottonseed oil, coconut oil, China wood oil, linseed oil, oiticica oil, and tallow. Among the fish oils may be mentioned menhaden oil, cod-liver oil, and in general oil from fish of the herring family, and more particularly sardine oil. It is not known just what compound is contained in these oils which becomes activated or modified into the particularly eflicacious material of the present invention, although it is known that these fatty oils contain some unsaturated groups'which under the influence of heat and/or oxidation partly saturate themselves ,with oxygen. If such oxidation is carried to completion, it will be productive of materials known in the a t as oxidized oils, polymerized oils, or ozonides; and it has been found by applicant that the ozonides are partly effective for the purpose, although larger quantities are required than of, the only partly oxidized fatty oils. It has long been recognized that natural fats or oils as they ,50

are chiefly those of stearic and palmitic adds,

versa.

but oleic acid and olein are also present. Applicant is not limited to any particular type of fatty oils, provided they have been activated, as for example by heat treatment, oxidation, ozonization, or polymerization.

Applicants invention therefore is primarily concerned with the discovery that the ozonides, and more particularly the partly oxidized natural fatty oils and their analogous compounds, as well as polymerized fatty oils, are active antioxidants or stabilizers when employed in connection with petroleum distillates or motor fuels. Of these, the products produced by partial heat oxidation of fatty oils have proved to be particularly effective. In order to 'produce these materials, a fatty oil'such as a fish oil, or a vegetable oil-for example, corn oilmay be heated in a suitable kettle at a temperature of, from 300 to 400 F. while at the same time air is blown through the heated oil in fine streams. An oxidizing and heating period of from 7 hours to 24 hours is usually sufiicient to produce asuitable antioxidant or preservative material. As the temperature is increased, the time may bedecreased, and vice As a test for satisfactory oxidation, a small portion of the heated oil may be withdrawn and cooled to room temperature, whereafter it may be tested between the thumb and forefinger for consistency or by actual viscosity test. A

' decided increase in viscosity will be noticeable.

The oil should preferably not be oxidized to that 1 stage where decided stringiness develops. In other words, the oxidation should rather be of a molecular type than a complete type, care being taken to control the chemical reaction incident to the oxidation so as to keep it from going to completion. Therefore is is desirable that the oil contain a partial oxidation product instead of the complete complex ozonides or oxidation products which are characteristic of the complete oxidation of such an oil. Applicant has been able to obtain much better results with the use of what may be called the moi-oxides of oils and fats, particularly those of a semi-drying nature. It is known that the oxidation reaction of a characteristic animal or vegetable oil or fat passes through an induction stage in which molecular oxygen is evidently added. This fact is recognized in organic and physiological chemistry and has been mentioned, for example, by,G. E.

Holm and H. Staudinger in fiber Autoxydation organlscher Verbindungen, III. fiber Autoxydation des asym. Diphenyl-athylens, Ber., 583: 1075-1079 (1925), and by Ross-Aiken-Gortner in Outlines of Biochemistry, pp. 640-644. Applicant has moreover found that those oils which have a naturally high content of vitamins A, D and E are particularly suitable for his purpose, although he is not prepared to say whether it is the oxidation products of these vitamins which play a role in' the activating reactions involved in his invention. However, the empirical fact remains that oils containing these vitamins have,

for some reason, an inherent chemical constitution which makes them particularly applicable to the practice of the present invention.

After the oils have been activated as hereinabove indicated, they are preferably dissolved in a sumcient amount by volume of a suitable diluent, which may be either a hydrocarbon, or a high-boiling or heavy synthetic-alcohol distillate which itself has the properties of an inhibitor, so as to produce a fluid mixture which can be accurately measured. The actual amount of activated fatty oil employed in motor fuels varies from to $5, part or, expressed in another way, from /2 pint to 1 gallon of the activated oil may be added to, say, 10,000 gallons of motor fuel which it is desired to preserve and stabilize. The amounts employed, it will be noticed, are extremely small, thus showing the very high effectiveness of the material of the present invention. The incorporation of the indicated quantities of the new stabilizing compound acts to prevent or retard deterioration of the motor fuels and preserves their clear, transparent appearance when they are exposed to light or unfavorable storage conditions, and particularly prevents the formation of milky or cloudy precipitates, while also preserving the antiknock or antidetonant rating of the motor fuel; in fact, it has been found that motor fuel containing a metallo-organic antidetonant, which ordinarily invention is shown. These tables strikingly demonstrate the efficacy of thematerials.

Table I I Exposure 3. Like 1+1 1. Straight run 2. Like 1+raw to light pt./40,000 acti- (homs) motor fuel oils Vated oils Vi Clear Clear Clear. Slightly cloudy- Slightly cloudy- Do. Cloudy. Cloudy Do. Milky Milky Do. Heavy precipitate. Heavy precipitate. 1130. o. Heavy precipitate.

Corn, soy bean, cottonseed, menhaden, sardine.

Exposure 4. Like 1+1 6. Like 5+1 to light it 10,000 activated ll i gfig pt./l0,000 ac- (hours) oils tivated oils 9. Cracked Exposure 8. Like 7+1 to light 7 Ethyl gasoline pt./10,000 actigasoline+gum (hours) vated oils inhibitor Clear.

Do. Do.

Slightly cloudy.

Cloudy. Heavy precipitate.

10. Like 9+1 11. Like 9+1 12. Like 9+1 Exposure pt./10,000 activated pt./l0,000 activated pt./10,000act1- to light oils+monobenzyl oils+ butyl paravated oils+ (hours) para-aminophenol aminophenol pyrogallol hol distillate Referring to Table I, it will be seen that there .are seventeen entries therein, corresponding to containing these plus certain well known individual gum inhibitors. For instance, test No. 1 covers a straight run motor fuel containing no added materials, being exposed to light for the periods of time indicated. It will be noticed that even after a half hour the material was slightly cloudy, while at the end of four hours there was a heavy precipitate.

In test No. 2 the same material as in test No. 1 was used, but there was added to it from one part in 40,000 to one part in 10,000 of the plain raw unactivated oils indicated in the footnote. These oils are the same ones which were employed to produce the activated oils of the present invention used in the later tests shown in the table. It will be seen that the results are precisely the same as those in test No. 1, showing conclusively that the raw oils do not have any inhibiting, stahilizing or protective effect whatsoever.

Test No. 3 covers the same motor fuel as used in tests No. 1 and No. 2, but here the present invention was practiced by adding to the motor fuel one part in 40,000 of the activated oils. It will be noticed that even after eight hours the materialwas still clear, and it took twenty-four hours to obtain a precipitate.

In test No. 4 the same motor fuel was employed, in'this case however adding one part in 10.000 of the activated oils of the present invention, and from the table it will be evident that dition of one part in 10,000 of the activated oils,

and it will be'seen that the material remained clear for eight hours.

. of the oxidized oils.

No. 7 was'a test made with standard tetraethyl lead motor fuel without any additions. This became slightly cloudy even in a half hour and had a heavy precipitate at the end of four hours. When treated as shown in test No. 8, however, by the addition of one part in 10,000 of the activated oils of the present invention, this material remained completely clear even at the end of twenty-four hours.

To demonstate the advantageous effect of the activated .oils of the present invention in connection with other gum inhibitors, test No. 9 was made, this being on cracked motor fuel containing a'standard form of gum inhibitor such as one of the particular compounds mentioned in tests Nos. 10-15, but without the use of any It will be seen that the use of the gum inhibitor was partly successful in keeping the motor fuel clear for an hour, but at' the end of two'hours, it was slightly cloudy, at the end of four hours it was definitely cloudy, and at the end of eight hours it contained a heavy precipitate. Tests Nos. 10-15 are particularly instructive, constituting six individual tests, in

each case one part in 10,000 of the activated oils of the present invention being used with the usual amounts .of the specifically mentioned gum inhibitors such as monobenzyl para-aminophenol,

etc. (see table). It will be noticed that, irrespective of which gum inhibitor was employed, the material remained entirely clear even at the end of twenty-four hours. These tests should be compared with test No. 9, in which the same gum inhibitors were used but the activated oils ofthe present invention were omitted. In connection with the last mentioned gum inhibitors, namely, the heavy synthetic alcohol distillate and the alkaline derivative thereof, these are the compounds particularly described and claimed in applicants copending application Serial No.,

171,893, filed October 30, 1937, and act not only as inhibitors but also as inhibitors of inhibitors. This heavy synthetic alcohol distillate is a'relatively high boiling mixture of compounds, in-

cluding higher alcohols, which is formed in small quantities in the catalytic synthesis of methanol from carbon monoxide and hydrogen. The alkaline derivative may be prepared by reacting the mixture with an alkali metal such as sodium or potassium.

Tests Nos'. 16- and 17 were made with a motor fuel containing iron carbonyl as the antide- Table II 1. Motor iuel+3 cc. Exposure to light tetraethyl lead 2. Like 1 but 3. Like 1+raw (hours) 1- U. 8. galexposed oils on (control, not exposed) 2 Not exposed... Cloudy Cloudy. 4 do Dense. Dense. 8 do Heavy precip- Heavy precipiitate. tate. 16 (Clean) -{3311;111:131 ??3't:::::::: 33123 13.0'7 lead 12.77 lead. 1155 {12.9 lead. 13.278 lead.

ilglotolglel cc. ra- Exposliilre ti; light 6 g ;t, ethy ieaclil per 6. Like 5(lliut ours ga on expose vated 9H8 (control, not

exposed) Cloudy. Dense. Heavy precipitate. Antiknock value 1313;313:3331: 3513;131:3333: 3923. Loss of metal None 12.0% lead. 10.0% lead.

16 M to f l 8. o r ue Expoallrre tr; light iziront calrboxiyl 9. Like 5;)(exours con ro no pose activated oils exposed) Clear Cloudy. ..do Heavy precipltate. .do do (Clear) Antiknock value. Lossol'metal None None Considerable as precipitate.

10. Like 8+ Exposure to light (hours) 1 put/10.000

activated oils 16 l Antikuock value Loss of metal The tests in connection with Table II were to show the loss of metal from a motor fuel containing a metallo-organic antidetonant such as either tetraethyl lead or a metallic carbonyl derivative. Test No. 1 was the control in which there was no exposure to light, but the material was kept for sixteen hours in the dark and 1 its antiknock value then determined by the testing methods of the American Society for Testing Materials, or its revised method L-3, showing that in two separate tests the motor fuel had an antiknock value of, 78.1 and 78.2, respectively. This fuel contained 3 cc. of tetraethyl lead per United States gallon.

In test No. 2 the material used in test No. 1 was exposed to light for the time indicated, and

it will be noticed that there was a loss of sub-.

.invention, employing one part in 10,000 of the activated oils. It will be noticed that even at the end of sixteen hours exposure the motor fuel was still clear, the antiknock value had not been decreased, and no lead had been lost, showing therefore the great eflicacy of even so small an amount of the activated fatty oils. of the present invention.

Tests Nos. 5, 6 and 7 were made with the same type of fuel as used in tests Nos. 1 through 4,

but only 1.7 cc. of tetraethyl lead per United States gallon was employed. This type of fuel corresponds to the so-called regular motor fuel. It will be seen that without the addition of the activated oils of the present invention there was a loss, in test No. 6, of 12% and respectively, of lead, while the use of one part in 10,000 of oxidized oils completely protected the motor fuel. The deterioration of fuel contain-' will be self-evident that it is not to be limited to this particular boiling point range, because it is equally applicable to motor fuels having lower or higher boiling point ranges, such as, for example, kerosene, Diesel motor fuels and lubricating oils on the one hand, and aviation fuels on the other hand.

The term glycerides in the claims is used in its general sense, which includes the natural oils produced by living organisms, either plants or animals, as distinguished from non-glycerides such as essential oil or from mineral oils.

The term activated" in the claims is intended to be descriptive of an oil whose properties have been modified by oxidation, ozonization, or heattreatment, or any two or all of these steps.

' Applicant does not care to submit any particular theory to account for the eflicacy of the materials and reports herein merely the results obtained by careful experimentation with the materials described.

Saving for himself such equivalents as will occur to those skilled in the art to which this invention appertains, applicant claims:

1. The process of preserving the antiknock value, color and transparency of a hydrocarbon motor fuel comprising hydrocarbons having a .boiling point within the gasoline range and me tallo-organic antidetonants which comprises incorporating therewith an activated oxidized glyceride in substantially the ratio of one part of said glyceride to from 1,000 to 80,000 parts of the motor fuel.

2. The process of claim. 1 eride is a vegetable oil.

3. The process of claim 1 in which the glyceride is a. fish oil.

4. A hydrocarbon fuel comprising hydrocarbons having boiling points within the gasoline in which the glycboiling range and a sufficient quantity of tetra ethyl lead to enhance its antidetonating properties, rendered stable by having incorporated therewith an activated oxidized glyceride in substantially the ratio of about one part thereof to from 1,000 to 80,000 parts of the hydrocarbon fuel.

5. The process of preserving and stabilizing a hydrocarbon motor fuel containing hydrocarbons having a boiling point within the gasoline range and a metallo-organic antidetonant which'comprises incorporating therewith an activated semidrying oil in substantially the ratio of one part thereof to from 1,000 to 80,000 parts of the motor fuel.

6. A hydrocarbon motor fuel containing hydrocarbons having a boiling point within the gasoline range and metallo-organic antidetonants and rendered stable by having incorporated therewith an activated oxidized semidrying oil in amounts of about one part thereof to from 1,000 to 80,000 parts of the motor fuel.

7. A hydrocarbon motor fuel containing hydrocarbons having a boiling point within the gasoline range rendered stable against time and light deterioration by incorporation therewith of an activated oxidized glyceride in substantially the ratio of one part of said oxidized glyceride to from 1,000 to 80,000 parts of the motor fuel.

8. A- hydrocarbon motor fuel containing hydrocarbons having a boiling point within the gasoline range rendered stable against time and light deterioration by incorporation therewith of a partly heat-oxidized oxidized glyceride in sub- 12. The process of preserving the antiknock value, color and transparency of a. hydrocarbon motor fuel comprising hydrocarbons having a boiling point within the gasoline range and metallo-organic antidetonants which comprises in- 1 corporating therewith an activated oxidized glyceride in an amount not substantially exceedin one part thereof to 1,000 parts of the motor fuel.

13. A hydrocarbon motor fuel containing hydrocarbons having a boiling point within the gasoline range, rendered stable against time and light deterioration by incorporation therewith of a gum inhibitor and an oxidized glyceride in an amount not exceeding one part thereof to 1,000 parts of m'ptor fuel.

14. The motor fuel recited in claim 13 in which the gum inhibitor is selected from the group consisting of heavy synthetic alcohol distillates and the alkaline derivatives thereof.

15. A hydrocarbon motor fuel containing hydrocarbons having a boiling point within the gasoline range and a metallo-organic antidetonant, rendered stable against time and light deterioration by incorporation therewith of an oxidized glyceride in an amount not exceeding one part thereof to 1,000 parts of the motor fuel.

16. The motor fuel recited in claim 15, in which the antidetonant is iron carbonyl.

1'7. The motor fuel recited in claim 15, in which the antidetonant is lead tetraethyl.

- FRANKLIN W. McCURRY. 

